To look at it another way, Sale needs to have two more years like 2012 to jsutify his contract. Forgetting about the give up of free agency, arbitration, etc. If I'm a team trying to win now and have deep pockets (and need pitching), I can easily justfiy Sale today as that team's GM.

How much would it cost on the free agent market to go and get a Sale of 2012? You're probably looking at $18MM per year for 5-6 years. If Sale's 2013-2014 mimic his 2012 and then he blows his arm out the winter of 2014--you essentially paid him $30MM over 4.5 yrs instead of overpaying a free agent who you can owe 3 times taht money too.

At least that's how I would justify it if I were a team like the Yankees or Rangers.

Bob

You forgot the package of prospects. The original point was getting a package like Tampa got for Shields. So Sale burns his arm out in 2014 and you say the money is not a big deal. Agreed. But the "Yankees or Rangers' not only would have lost money, they would have gave up their top prospects as well.
The question you totally missed is this: If Sale is a risky acquisition long term for a contending team, are they still going to offer the Sox a great package of prospects in return. If yes, then I agree you trade him. But he is a legit Number One starter. Accepting less a package because his value is limited due to fear of injury is crazy. Then you hold him.